Tip for propellers



Jan. 11,1927. 1,614,186

N. s. CLAY TIP FOR PROPELLERS Filed Oct. 2'7, 1920 INVENTOR WITNESSES:

Patented Jan. 11, 192 7. I

UNITED STATES PATENT OFFICE.

NOBLE S. CLAY, OF WILKINfiBURiG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TIP FOR PBOPELLERS. Application filed October 27, 1920. Serial No. 419,812.

My invention relates to propellers, and In the accompanying drawings, forming more especially to propellers employed in a part hereof, and in which similar referthe propulsion of airplane ence characters denote similar parts,

Airplane propellers are subject. to de- Fig. 1 is an elevational view of a propeller 6 structive influence, such as contact with having detachable tips;

plant growth, rain, or spray, with the con- 1 Fig. 2 is an enlarged view of one of the sequent result that the ends and leadin tips shown in Fig. 1; and edges are speedily damaged and. destroye Fig. '3 is an elevational view of an end To lengthen the life of such'propellers, it portion of a composite or wood propeller has been proposed to provide metal tips on showing metal inserts molded into or formed the ends thereof, such tips being mounted on the propeller blade and adapted to hold thereon by screws-or rivets, or deposited by a molded or metal tip in position. electrolysis, but it was found that the vi- Referring to Figs, 1 and 2, a propeller bration and slight bending'of the propeller body 1 may have tips 2 secured thereto by blades caused cracking and destruction of screws or rivets 3 having countersunk heads the'tipsand propeller ends. to avoid projections on the surface of the ,In-the application of tips to propeller propeller. In the embodiment shown in blades, it is desirable to replace worn parts, Figs. 1 and 2, the metal tip 2 is molded to audit is among the objects. of my invention the body portion 1 and may be further se- 7 to provide tips for the leading edges of procured by screws 3, if 'sodesired.

- pellers which have a hard, wear-resistant In the form shown in Fig. 3, metal strips surface, yet are flexible, so that slight bendor inserts 4 are molded into the body 1 of the ing or vibration of the propeller blades will propeller and the molded or metal tips 2 are not crack them and which may be readily secured'thereto by screws or rivets 3.

replaced An example of the. application of my in- It is another object of my invention .to vention is as follows: provide composite propellers for naval or Layers of duck impregnated with a soluother use with non-corrosive molded orble, fusible phenolic, condensation product metal tips. and cut to the proper shapes, are built up It is a further objectof m invention to. to form a propeller body. Metal strips or provide propellers with "dura le tipsmoldinserts 4 are fitted between layers on the ed to the propeller body. propeller ends at or near the surface thereof In practicing my invention, I provide and the whole structure is subjected to heat means for securing tips to propeller blades and pressure in amold to render the mass 85 in such manner as to prevent the formation insoluble and hard. Metal tips 2 formed to of cracks in, or other damage to, thebody the desired shape are secured to the inserts ort-ion. I may utilize preformed or molded 4 by means of screws or rivets 3. tips of the desired sha e embodying a binder This structure has several advantages in such as aphenolic con ensation product, and that the metal tips are more securely fasa. fibrous filler, preferably a duck materialtened to the propeller ends, thus eliminat-' The tips may be molded to correct shapes ing the danger of their becoming loose or for mounting and suitable openings may be cracking. T is construction also allows tips formed therein for the insertion of screws which have become damaged to be removed or rivets. For severe service,- .a small perby simply removing the screws which hold centage of powdered silica may be added to them in place and then securing new tips the molding composition or may be sprinin their stead. kled on the surfaces of the material before Although I have shown and described the final molding, thereby producing avery specific embodiments of my invention, it is hard, wear-resisting surface onjhe tips. I to be understood that my invention 15 not the case of composite propellers, Imay mold limited to the exact structure herein set metal tips into the body ortion or secure forth as various changes can be made in dethem to metal inserts 'mo ded into the mitails of. construction without departing carta body. from the principles thereof. For instance,

metal or molded tips may be secured to metal inserts in Wooden propellers, the inserts being fitted between plies of wood and the tips secured thereto by suitable screws or rivets. Metal tips may be molded directly on the composite propeller, or tips of composite material may be' molded to woodon or composite propellers. It is obvious that a molding composition other than a phenolic condensation product and fibrous material may be used.

Although I prefer to form my molded tip with silicious material incorporated there in, I may omit such material or substitute therefor other hard, Wear-resisting materials such as emery, corundum, carborundum, and the like.

I claim as my invention:-

1. A propeller comprising a body portion, inserts molded in the ends thereof, tips mounted on said ends, and means for securing said tips to said inserts.

2. A propeller comprising a body portion of fibrous material and a phenolic condensation product, inserts molded in the ends thereof, premolded tips mounted on said ends, and means for securing said tips to said inserts.

product and wear-resisting material.

4. A propeller comprising a body portion, and tips comprising a wear-resisting molding mixture, saidiips being molded on the ends of said body portion.

5. A molded propeller comprising fibrous material and a phenolic condensation product, inserts molded in the ends thereof, premolded tips on said ends and means to secure said tips to said inserts.

6. A molded propeller of fibrous material and a phenolic condensation product, inserts molded in the ends thereof, premolded tips comprising a wear-resisting material and a phenolic condensation product on said ends and means for securing said tips to said inserts.

In testimony whereof, I have hereunto subscribed my name this 14th day of October, 1920.

' NOBLE S. CLAY. 

